diff --git a/image/Image.cpp b/image/Image.cpp
index 6db7822b2b6d..f91778764166 100644
--- a/image/Image.cpp
+++ b/image/Image.cpp
@@ -169,5 +169,31 @@ ImageResource::SendOnUnlockedDraw(uint32_t aFlags)
   }
 }
 
+#ifdef DEBUG
+void
+ImageResource::NotifyDrawingObservers()
+{
+  if (!mURI || !NS_IsMainThread()) {
+    return;
+  }
+
+  bool match = false;
+  if ((NS_FAILED(mURI->SchemeIs("resource", &match)) || !match) &&
+      (NS_FAILED(mURI->SchemeIs("chrome", &match)) || !match)) {
+    return;
+  }
+
+  // Record the image drawing for startup performance testing.
+  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
+  NS_WARNING_ASSERTION(obs, "Can't get an observer service handle");
+  if (obs) {
+    nsCOMPtr<nsIURI> imageURI = mURI->ToIURI();
+    nsAutoCString spec;
+    imageURI->GetSpec(spec);
+    obs->NotifyObservers(nullptr, "image-drawing", NS_ConvertUTF8toUTF16(spec).get());
+  }
+}
+#endif
+
 } // namespace image
 } // namespace mozilla
diff --git a/image/Image.h b/image/Image.h
index 87d771bd732c..f6a7576bad1e 100644
--- a/image/Image.h
+++ b/image/Image.h
@@ -318,6 +318,11 @@ protected:
 
   void SendOnUnlockedDraw(uint32_t aFlags);
 
+#ifdef DEBUG
+  // Records the image drawing for startup performance testing.
+  void NotifyDrawingObservers();
+#endif
+
   // Member data shared by all implementations of this abstract class
   RefPtr<ProgressTracker>     mProgressTracker;
   RefPtr<ImageURL>            mURI;
diff --git a/image/RasterImage.cpp b/image/RasterImage.cpp
index a2efbef9ee07..20f830678030 100644
--- a/image/RasterImage.cpp
+++ b/image/RasterImage.cpp
@@ -1691,32 +1691,6 @@ RasterImage::GetFramesNotified(uint32_t* aFramesNotified)
 }
 #endif
 
-#ifdef DEBUG
-void
-RasterImage::NotifyDrawingObservers()
-{
-  if (!mURI || !NS_IsMainThread()) {
-    return;
-  }
-
-  bool match = false;
-  if ((NS_FAILED(mURI->SchemeIs("resource", &match)) || !match) &&
-      (NS_FAILED(mURI->SchemeIs("chrome", &match)) || !match)) {
-    return;
-  }
-
-  // Record the image drawing for startup performance testing.
-  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
-  NS_WARNING_ASSERTION(obs, "Can't get an observer service handle");
-  if (obs) {
-    nsCOMPtr<nsIURI> imageURI = mURI->ToIURI();
-    nsAutoCString spec;
-    imageURI->GetSpec(spec);
-    obs->NotifyObservers(nullptr, "image-drawing", NS_ConvertUTF8toUTF16(spec).get());
-  }
-}
-#endif
-
 void
 RasterImage::NotifyProgress(Progress aProgress,
                             const IntRect& aInvalidRect /* = IntRect() */,
diff --git a/image/RasterImage.h b/image/RasterImage.h
index c3e4a80fabf4..8796b031dffd 100644
--- a/image/RasterImage.h
+++ b/image/RasterImage.h
@@ -317,11 +317,6 @@ private:
 
   void UpdateImageContainer();
 
-#ifdef DEBUG
-  // Records the image drawing for startup performance testing.
-  void NotifyDrawingObservers();
-#endif
-
   //////////////////////////////////////////////////////////////////////////////
   // Decoding.
   //////////////////////////////////////////////////////////////////////////////